Abundance of the nation's natural resources has decreased because humans have required energy from fossil fuels such as coal, oil, and natural gas. Fossil fuel is used to excess. Thus the pollution from using energy will lead to global warming. Therefore, countries are increasingly aware of the urgent need for energy-efficiency improvements. For this reason, heat exchangers are studied and improved for enhanced heat transfer performance. The literature review showed that scientists and researchers have interest in the research problems related to heat exchangers for enhancing heat transfer. Presently, the geometry of the heat exchanger for use in limited space is increasingly important. Thus, the heat exchanger's design is a challenging subject for further investigation in order to improve technology. The economizer is a heat exchanger used in many industrial applications. An economizer can improve cost savings by waste heat recovery. It is a spiral fin-and-tube heat exchanger. The spiral fin is a surface that extends from the tube to increase heat transfer surface area. Hence, the improvement and development of a spiral fin for heat transfer enhancement is the aim of researchers. A thermal system's increased energy efficiency will have a significant effect on increasing heat transfer performance of heat exchangers. Moreover, it will lead to a more compact heat exchanger for limited space applications, which reduces cost of manufacture. Therefore, the spiral fin-and-tube heat exchanger for high heat transfer performance will use the optimal type of louver spiral fin, herein called a “Mixed Louver Spiral Fin-and-Tube Heat Exchanger”. Additionally, this kind of louver spiral fin is used in the new types of heat exchangers. It will lead to innovation in economizer design in the twenty-first century to respond to world energy consumption.
The energy crisis is one motivation for improvement of energy efficiency in industrial applications. Therefore, the research about the heat exchanger improvement has a significant effect on studying heat transfer performance enhancement. Since a heat exchanger may consist of a tube and a fin, improving the fin patterns is one way to augment the heat transfer performance on the air side of the heat exchanger. Furthermore, the tube arrangement, type of working fluid, and material of the heat exchanger itself has significance for heat exchanger design. The spiral fin-and-tube heat exchanger is the type of fin-and-tube heat exchanger favored in industrial application.